83 SC - mystery part & wire ID

[83_Silberpfeil]

While figuring out why the fuel pump on my SC is not working, I've stumbled across one part and one wire that are mystery to me.

First is this device here that I found near the cross member towards the driver side. It looks like a speaker for an alarm to me. Does anyone recognize? It is connected to a pair of very thin wires. I know my car does have an alarm --- perhaps aftermarket. I checked for the stock Porsched installed alarm speaker --- usually sitting at center of cross member, but didn't find anything.



The next item was a wire that was inserted into a relay socket. See fotos here. I removed this socket just out of curiosity. Then, noticed that this wire inserted into one of the pin slots; the insulation was removed, so definitely trying to make an electrical connection there. What could this be used for? Alarm again?

[proporsche]

just get rid of it..as you can see mickey mouse install..;-)it is part of an old alarm system as you know ...
Ivan

[PeteKz]

Agree with Ivan. Those aftermarket alarm systems depended greatly on the quality of the installer, and may of those were "hack jobs." It's likely to cause you electrical problems at some point.

[porschedude996]

I ripped the 1980’s alarm out on my ‘83 911SC after my purchase in Oct 2022. While throwing the horn and other ca-ca away, I about froze. What if there was something that would disable the car when I removed said ca-ca. Good news was it didn’t affect anything.

[83_Silberpfeil]

Thanks for taking a look, and your assessment/advice. That device was very light, all plastic, so likely a horn/siren. I'd like to get rid of it, but have same thoughts as @proporchedude996 --- what if it is connected to some other critical components that could immobilize the car. I'm currently having start-up issues, and diagnosing the fuel pump not starting. Will be taking a very cautious approach.

QUESTION: what about that wire in the second and third fotos in the opening post? Does that look like it is also for car alarm?

[porschedude996]

Take pictures and notes of the foreign stuff you want to remove. The relay socket repair is necessary, but unless they installed and interrupt to the fuel pump or CDI, I don’t think it is your issue with starting the engine. Remove Fuel Pump relay and bypass. If the pump runs and the CDI are making noise, sounds like it was only a noise maker Alarm. Meaning nothing is disabling the car from starting and driving.

Fuel pump relay bypass.

Fuel Pump Relay Bypass

[proporsche]

as above porschedude said...follow the wires and take pictures we will help you..fuel pump fuse is 6th from the windshield...
upper connection is vacant on that white house

Ivan

[83_Silberpfeil]

Thanks Ivan, yes, that's a logical approach.

Yup, the 6th fuse is Fuse #16 per Bentley's.

Interesting you noticed vacant connections on the upper side of that white fuse. There are 2 or may be 3 where the upper connections are vacant. I don't see any looss wires near those vacant spots to suggest that a wire fell out.

Originally Posted by proporsche

as above porschedude said...follow the wires and take pictures we will help you..fuel pump fuse is 6th from the windshield...
upper connection is vacant on that white house

Ivan

[porschedude996]

it may have a bridge plate. Look close and you may see a small u-shaped piece of brass that spans to another fuse.

[83_Silberpfeil]

What is this orange box that I'm pointing at with the telescoping magnet?

Another mystery part/component to ID. I found this under the FRUNK directly underside of the wipers and in front (other side) of the dashboard gauges.

Is it the brain or main processor for an aftermarket alarm? Or is it something that came out of the factory?

In the opening post, first foto, I indicated that my car likely has an aftermarket alarm.

Thanks!

[proporsche]

yup part of the alarm crap...remove it but show us the wires..so we can see what the heck was connected to it
Ivan

[porschedude996]

The poor workmanship shows. Just bury the box in amongst the other stuff. Owner will never know.

[83_Silberpfeil]

That's how lots of mobile audio shops operated back in the days!

BTW --- love your red 83 coupe! Especially the all black trimming around all of the windows --- it just goes so well with the red, and makes it look very sporty. The trimmings around my silver 83 are black (rubber?) at the rear windows, but the main and front 1/4 glass are metallic/silver. Not sure how it got that way, or which way is stock from factory. But, would be great to make mine black like yours.

Originally Posted by porschedude996

The poor workmanship shows. Just bury the box in amongst the other stuff. Owner will never know.

[83_Silberpfeil]

Thanks Ivan! It is on the to-do list. I'm just as curious as everyone else. Stay tuned.

Originally Posted by proporsche

yup part of the alarm crap...remove it but show us the wires..so we can see what the heck was connected to it
Ivan

[porschedude996]

Originally Posted by 83_Silberpfeil

That's how lots of mobile audio shops operated back in the days!

BTW --- love your red 83 coupe! Especially the all black trimming around all of the windows --- it just goes so well with the red, and makes it look very sporty. The trimmings around my silver 83 are black (rubber?) at the rear windows, but the main and front 1/4 glass are metallic/silver. Not sure how it got that way, or which way is stock from factory. But, would be great to make mine black like yours.

Thanks 83_Silberpfeil, I’m partial to the black trim. It does have a piece or two one the outside. Chrome Ring and Nut on the antenna.

[aoncurly]

I had a Hofco alarm installed back in the 80's. Yours is probably similar to mine in that it has a couple of relays wired in. Usually, there is a cutoff at the ignition and one for the fuel pump. I've thought about pulling mine out as well, but the juice ain't worth the squeeze. I just removed the fuse for the alarm (mine was located at the fusebox in the frunk) and leave it alone.

[83_Silberpfeil]

Thanks @aoncurly. I will take a closer look. Try to grab the box and see if there are any branding on it, if it is Hofco. And, also trace the wires out of the box/connectors to see if I find a fuse that I can remove.

At the moment, there is also an alarm horn/speaker handing down from under the car. When I dropped the metal skid plate down behind the fuel tank, this speaker/horn dropped down, hanging by its wires. I'll need to look into cutting the wires and removing the horn before I reinstall the skid plate.

Originally Posted by aoncurly

I had a Hofco alarm installed back in the 80's. Yours is probably similar to mine in that it has a couple of relays wired in. Usually, there is a cutoff at the ignition and one for the fuel pump. I've thought about pulling mine out as well, but the juice ain't worth the squeeze. I just removed the fuse for the alarm (mine was located at the fusebox in the frunk) and leave it alone.

[aoncurly]

I think the alarm fuse is in the white holder shown in your picture by your fuse box, near the red relay. If it's a Hofco, it will be on the plastic box, either saying HOFCO I, II, or III. There might also be a shake or tilt switch which is a silver metal box located in the frunk near your spare tire.

[83_Silberpfeil]

@aoncurly - You are spot on! I spent an hour under the hood last night. Was able to remove the orange box, the 'main brain' of the alarm system. Indeed it is a HOFCO III.

Was this a Porsche factory install, or a USA dealer install?

It took me 5 min to carefully angle/align the orange box out of that tight space. Then, unplugged the two flat connectors, and opened up the box.

Then, traced the paths of each of the 6 wires from the connectors.

I detailed where each of the six wires connect into in this separate thread here:
HOFCO III alarm in an '83 SC

Originally Posted by aoncurly

I think the alarm fuse is in the white holder shown in your picture by your fuse box, near the red relay. If it's a Hofco, it will be on the plastic box, either saying HOFCO I, II, or III. There might also be a shake or tilt switch which is a silver metal box located in the frunk near your spare tire.